Performance of NDT Techniques in Appraising Condition of Reinforced Concrete Bridge Decks

The colossal backlog of deteriorated concrete bridge decks draws attention to the importance of nondestructive testing (NDT) technologies as potential bridge condition assessment tools. The selection of NDT techniques to evaluate the current state of bridge decks is a decision variable. The foremost objective of this study was to conduct a comparative analysis of the common NDT methods for detecting subsurface defects in concrete bridge decks, particularly rebar corrosion, delamination, and cracking. Thus, impact echo (IE), ultrasonic pulse echo (UPE), ground-penetrating radar (GPR), infrared thermography (IRT), and half-cell potential (HCP) were appraised and ranked from the perspective of five performance measures: capability, speed, simplicity, accuracy, and cost. The information sought to identify the significance of the factors affecting the analysis was collected through a survey questionnaire of bridge engineers having extensive NDT experience. In order to incorporate the imprecise information and vagueness of human judgment in decision-making, the fuzzy analytical hierarchy process (FAHP) was employed. The fuzzy preference program (FPP) nonlinear method was adopted to determine the relative weights using MATLAB. The outcomes revealed that each technology can address specific bridge challenges. For instance, some technologies are associated with simplicity and lower cost, whereas others excel in accuracy or speed. Thus, a decision regarding the selection of a technology is guided by the objectives of the assessment and the most important performance parameters. The proposed methodology should assist bridge stake-holders in the rational appraising of NDT technologies for bridge decks based on a wide scope of information sources. (C) 2017 American Society of Civil Engineers.